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Beware buying new GM Rockers

 
Old 10-13-2018, 02:29 PM
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Georgies
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Default Beware buying new GM Rockers

Is this normal?

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Old 10-13-2018, 02:43 PM
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what are you trying to show us?
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Old 10-13-2018, 02:48 PM
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chris308
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my guess is thats the tiny needle bearings making that noise. get yourself a BTR trunion or Straub kit and swap out them on your old rockers and return the rockers you bought from the dealer.
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Old 10-13-2018, 05:06 PM
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Georgies
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I have a CHE trunnion kit already. Gonna swap out the bad rocker with this one and use the currently installed trunnion from CHE.

I just wanted to know if its normal to be that loose. Its a brand new rocker...
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Old 10-13-2018, 05:50 PM
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just did a trunnion bushing kit on mine
nothing to fall into the oil pan
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Old 10-14-2018, 02:29 PM
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Originally Posted by Georgies View Post
I have a CHE trunnion kit already. Gonna swap out the bad rocker with this one and use the currently installed trunnion from CHE.

I just wanted to know if its normal to be that loose. Its a brand new rocker...
I would say so, since after I installed the Straub bushings in my engine, it got notably quieter.
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Old 10-14-2018, 04:48 PM
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redzg
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I'm curious why this is a 'Beware buying new GM Rockers' issue if we don't know whether it's normal or not? I assume the needles have some lubricant from manufacture, but aren't as flooded as they will be during operation.
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Old 10-14-2018, 06:29 PM
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Spaceme1117
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That is normal. There is a little bit of play in the needles. Soak in some oil and you won't hear anything.

Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure

But manufactures sure have made a ****-load of money off this myth.
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Old 10-14-2018, 09:11 PM
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redzg
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Originally Posted by Spaceme1117 View Post
IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull.
It does seem strange that GM would use what would intuitively seem a more expensive bearing methodology. That said, I have seen other applications where needle bearings in short oscillating rotations, such as a rocker arm, quickly wore on the shaft (or trunion). Full rotation would spread the wear better, but that's not how rockers work. I do note that small displacement, high RPM motorcycle engines have switched con rod bearings from needle to shell bearings, reportedly because a properly lubricated shell bearing has less friction than a needle bearing.
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Old 10-15-2018, 11:43 AM
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Originally Posted by Georgies View Post
I just had to say it " a cuco racha - a cuco racha"......... LOL!!

I would say its normal. No lube in the needle bearing.

Last edited by Bill Curlee; 10-15-2018 at 12:17 PM.
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Old 10-15-2018, 11:55 AM
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Originally Posted by redzg View Post
It does seem strange that GM would use what would intuitively seem a more expensive bearing methodology. That said, I have seen other applications where needle bearings in short oscillating rotations, such as a rocker arm, quickly wore on the shaft (or trunion). Full rotation would spread the wear better, but that's not how rockers work. I do note that small displacement, high RPM motorcycle engines have switched con rod bearings from needle to shell bearings, reportedly because a properly lubricated shell bearing has less friction than a needle bearing.
For some reason, GM did go with what appears to be a "strange" design. However, they designed it to operate within a certain range of rotational motion, a LOT less than 360*, and with relatively low spring pressures. The problems usually occur when "camming it up"....
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Old 10-15-2018, 01:23 PM
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Georgies
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I agree with the above. I wasn't sure if it was normal, and just wanted to to share my observations. I went with the CHE trunnion upgrade as it look to be a good upgrade and choice of company.
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Old 10-15-2018, 01:34 PM
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Originally Posted by Spaceme1117 View Post
That is normal. There is a little bit of play in the needles. Soak in some oil and you won't hear anything.

Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure

But manufactures sure have made a ****-load of money off this myth.
This 100%. There is so much FUD (Fear, Uncertainty, and Doubt) spread about the GM rockers by aftermarket companies looking to make a buck, selling their products as preventative maintenance to guys with stock or small aftermarket cams. You'll never prove to me that any of the aftermarket rocker trunnion bearing or bushing kits are more durable or reliable than GM's in stock/small cam cars. The only reason I can see to run an aftermarket rocker setup is with a big cam and stiff springs, in which case you'll be doing regular valvetrain maintenance at much shorter intervals anyway.
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Old 10-15-2018, 04:05 PM
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Georgies
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What do you mean by maintenance?

im running a MS4 cam and pac dual valve springs and TI retainers along with the CHE trunion bushings...
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Old 10-15-2018, 05:29 PM
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Originally Posted by TastyBacon View Post
This 100%. There is so much FUD (Fear, Uncertainty, and Doubt) spread about the GM rockers by aftermarket companies looking to make a buck, selling their products as preventative maintenance to guys with stock or small aftermarket cams. You'll never prove to me that any of the aftermarket rocker trunnion bearing or bushing kits are more durable or reliable than GM's in stock/small cam cars. The only reason I can see to run an aftermarket rocker setup is with a big cam and stiff springs, in which case you'll be doing regular valvetrain maintenance at much shorter intervals anyway.
Actually there is LOTS of documentation on LS1.com of failures. This usually is not issue with a stock engine.... but stiffer valve springs and more aggressive camshafts make this problem come to the surface. when I bought my car... I spoke to my old neighbor about it (Kurt Urban..... yeah THAT Kurt Urban) he told me to do it and get rid of the "yellow springs" just for peace of mind since I pulled one of my heads to fix a cross threaded sparkplug the previous owner failed to mention LOL!
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Old 10-15-2018, 06:47 PM
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Originally Posted by Georgies View Post
What do you mean by maintenance?

im running a MS4 cam and pac dual valve springs and TI retainers along with the CHE trunion bushings...
Inspecting/replacing valve springs. I think TSP quotes valve spring life of the MS4 at around 30k, but it really depends how you use it; they should be checked or replaced sooner.

Originally Posted by ASRoff View Post
Actually there is LOTS of documentation on LS1.com of failures. This usually is not issue with a stock engine.... but stiffer valve springs and more aggressive camshafts make this problem come to the surface. when I bought my car... I spoke to my old neighbor about it (Kurt Urban..... yeah THAT Kurt Urban) he told me to do it and get rid of the "yellow springs" just for peace of mind since I pulled one of my heads to fix a cross threaded sparkplug the previous owner failed to mention LOL!
I know stock rockers fail more frequently with big cams and stiff springs. You are missing my point. I'm talking about companies marketing trunnion rebuilds as preventative maintenance to people with stock/small cams, warning them to get rid of ticking time bomb GM rockers when in fact, in the case of the needle bearing trunnion rebuilds, the aftermarket parts were the ticking time bombs. Now everybody is switching from needle bearings to the bronze bushings, and they seem to be better, but I'll re-state my previous point: you'll never prove to me that any of the aftermarket rocker trunnion bearing or bushing kits are more durable or reliable than GM's in stock/small cam cars.

Just out of curiosity, which rocker trunnion kit did Kurt recommend / you install?
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Old 10-15-2018, 07:20 PM
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Georgies
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How do you check the springs?
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Old 10-15-2018, 08:27 PM
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ASRoff
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He dident.... just said a trunnion kit.... I got smith bros..... its not like I'm running endurance racing... I have a set of PAC 1218 beehives to get rid of the yellows... I just like my junk to be bulletproof even if its just to get me to work and back 90% of the time.
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Old 10-16-2018, 09:51 AM
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Originally Posted by ASRoff View Post
... I just like my junk to be bulletproof even if its just to get me to work and back 90% of the time.
THAT, I can agree with!!

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Old 10-16-2018, 04:01 PM
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Originally Posted by Georgies View Post
How do you check the springs?
I pull mine every two years and check:
- free length
- load at seated length
- load at open length
- excessive tilt at either end
- inspect coil for cracking
I go overboard and check the inner and outer springs separately, and use an MTS universal testing machine to make the measurement.
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